Process of making pure zinc oxid.



'WALIJEMA'R AS131 033 PHILADELPH m PRGCESS fill MAKING L' UBE 251N132 C No Drawing.

3'0 175 whom it may concern:

it known that I, lVAii-DEMAR Assr, a, subject of the Emperor of Russia, residing in the city of l hilarlelphia, in the county of 5 lhiladelphis and State of Pennsylvania, have invented a certain new and useful Process of ii'iaking Pure Zinc @izid of which the following is a specification.

The principal object of the present inven '10 tion is to provide not only for obtaining pure zinc oxicl hut also for decomposing the salt or salts employed for that purpose, tans making a valuable product, ancla' the same time coi'iserring the caustic alkali for reuse.

.fsccorcling to my invention a zincate soluis decomposed by the aila'lition of a salt salts, thereby precipitating pure zinc 01c; forming a caustic alkz li solution in which. the salt or salts are inert and (le- 2o composing the salt or salts in an appropriate men or by an appropriate, agent inactive in respect to the caustic allo li solution to form valuable product also inert in the caustic ellreli solution.

For the who of further eiqilanation referi my to an illustrative trample are obvious, and in t: v will he assumed in t the 3s zinc'ote solution was decomposed lay the mlrlition of solution of sodium cal-inmate, thus itating pure zinc oxid and leevin r filtration a mother liquor sodium hydrate and sotlinm tie present invention, and as a part liquor, after the recovery of the pure zinc oxitl consists of l lefil l, Na CQ, and the addition of lime causes the following reaction 50 in the mother liquor:

NaflU +CaU+H O:CaCo +2NaOH. The sodium hydrate formed in the reac tion of course adds itself to the sodium hy- 55 dz ate present in the mother liquor prior to the addition of the lune, and the caustic Specification of Letters latent.

is inert and can he readily the invention in a case Application filed October 28, 914. Serial 5'0.

alkali can be reused in making silicate Mon and for other purposes. The sodium. carbonate is converted into the rolurhle product caustic sosle and calcium carhonr filtration. bf course caustic used instead is the squirrel. sods. N In the practice 0" e "are of zincate solution is not lino may he made by (lissolvin l Q n arterial or metallic nine in a calist solution. If the zinc present in nal material as sue preliminarily be converted into zis roastin 3 or a mother liquor is filtered on.

liquor then sohjeetecl which its caustic alkali 1t kali solution. An exam the addition lime, as one been i i which results in the. formation 0' alkali, a valuable product, anti cs1 honate, and. these are inert in caustic alkali soln'ion in w formal. The caustic all-tall solo filtered from the calcium some if clesireii evaporated for W. By the zinc product is OXKC it will he obvious to those skilled in art that modifications may" he m2" practice of the herein oesc ilml process n;

Haring thus rlescrihefil the lore ion, l claim is:

1. The process of making pure zinc onirl and recovering the 'anstic alkali solution and obtaining a valuable pro-(loot or proclncts, which consists in decomposing a moo ate solution by the addition of a solution of a salt, inert in caustic alkali solution substantially as described, thereby precipitating pure zinc oXid and forming a caustic alkali solution in which said salt is inert, separating the pure zinc oxid from the mother liquor, subjecting the mother liquor to treatment inert in respect to the caustic alkali andadapted to decompose the salt and form a product or products, and recovering the caustic alkali and product or products.

2. The process of. obtaining pure zinc oxid and recovering the caustic soda solution and making more caustic soda and corbonate of calcium, which consists in decomposing a zincate solution by the addition of a solution of sodium carbonate thereby precipitating pure zinc oXid and forming a caustic soda solution in which carbonate of calcium is inert, separating pure zinc oxid from the mother liquor, treating the mother liquor with lime which decomposes the s0- dium. carbonate forming caustic soda and calcium carbonate, and separating the calcium carbonate to recover caustic soda.

In testimony whereof I have hereunto signed my name.

WALDEMAR ASE Witnesses:

CLIFFORD K. CASSEL, FRANK E. FRENCH. 

